Turns out the command is: (ignore PS C:\>, that’s just to indicate a Powershell)

PS C:\> $PSVersionTable.PSVersion

No way I’m going to remember that. Luckily, StackOverflow user @ADTC mentioned he made a function to output the version.
Open notepad and write the function to the file specified from the $profile path.

PS C:\> notepad $profile

Insert the function:

function psver {
$PSVersionTable;
$PSVersionTable.PSVersion
}

Reload Powershell by running

PS C:\> . $profile

Now you can enter psver to output the version. Beautiful!

If you got an error when running notepad $profile that the file can’t be found, then simply enter $profile in your Powershell window to output the path and create the file manually in Windows Explorer.